Indu start travelling towards east and stops after 35 km and turns right and walks another 15 km

Indu start travelling towards east and stops after 35 km and turns right and walks another 15 km and again turns right and walk 15 km and again turns right and walk 15 km and then stops. What is the minimum distance Indu has to walk to reach the starting point?
(a) 35 km
(b) 30 km
(c) 20 km
(d) 25 km